Electrical plug and socket connectors



Dec. 14, 1965 w. c. J. ESSER ETAL 3,223,961

.ELECTRICAL PLUG AND SOCKET CONNECTORS Filed Feb. 26, 1962 nited StatesPatent 2 Claims. 61. 339-223 This invention relates to electrical plugand socket connectors, and more particularly to an improvement in aresilient detent for releasably securing the parts together.

Connectors of this nature are particularly suitable and adaptable forconnecting high tension conductor cables to automotive distributor headsor the like, the sockets being disposed in insulating sleeves fixed inthe heads.

It is desirable for the plugs which are attached to the ends to theelectrical cables, to be firmly and securely, but releasably, retainedin the sockets. In known connectors of this type the plug usually hasseveral detent elements which have the same axial location along theplug and thus operates simultaneously as a unit when the plug is engagedor disengaged from the socket. The forces required to depress thedetents thus reach their highest values simultaneously during the plugwithdrawal and can become so high as to render the plug difiicult toremove from the socket. An object of the invention is the provision of aplug which can easily be removed from the socket and is of simpleconstruction while being rugged in use and foolproof in operation.

According to the invention a recess in the socket and the detents of theplug are so arranged that the forces required to depress the detents donot reach their highest values simultaneously.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich is described an embodiment of the invention; it is to beunderstood, however, that the embodiment is not intended to beexhaustive nor limiting of the invention but is given for purposes ofillustration in order that others skilled in the art may fullyunderstand the invention and the principles thereof and the manner ofapplying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions of a particular use.

The preferred embodiment will now be described by way of example withreference to the accompanying drawing in which:

FIGURE 1 is a perspective view of the connector plug member;

FIGURE 2 is a top plan view of the plug member;

FIGURE 3 is an end view of the plug as it is shown in FIGURE 2;

FIGURE 4 is a side elevational view of the connector plug memberdisposed in an insulating sleeve, the socket member and the sleeve beingillustrated in longitudinal section.

In a preferred embodiment of the invention, the detents are formed asarcuate peripheral ribs on the plug body, the cooperating recess being agroove in the socket extending parallel to the ribs.

The plug is constituted by a cylindrical metal ferrule 2 which isreceived in the bore 4 of a socket 6, and receives the end of aninsulated cable 8.

The plug is preferably a cylindrical ferrule substantially the length ofwhich is arranged to surround the cable to which it is attached so thatthe ferrule is not deformed in the event the cable is pulled in thetransverse direction of the ferrule.

A triangular spear 10 cut from the wall of the ferrule 2 has been bentat a right angle inwardly of the ferrule 2 piercing the insulation 12 ofthe cable 8 and extending into the core 14 of the cable to provide apermanent electrical connection between ferrule 2 and core 14. Furtherspears 36 or the like have also been cut from the wall of the ferrule 2and have also been bent inwardly of the said ferrule, and protrude orextend into the insulation 12 to prevent relative axial movement betweenthe cable 8 and ferrule 2. As best seen in FIGURE 2 the ferrule 2 has arecess 16 from the walls 18 and 20 of which extend two opposed tongues22 and 24. The tongue 22 has been bent to provide an arcuate detent rib26 which is resiliently depressable and extends in a circumferentialdirection of the ferrule 2 and is wedge shaped as seen in cross-section.A similar detent rib 28 on the tongue 24 is displaced from the rib 26 inthe axial direction of the ferrule 2. The detent ribs 26 and 28 are bothreceived in a circumferential groove 30 of semicircular cross-sectionalshape on the internal surface of the socket member 6 as can be seen inFIGURE 4. T he groove 30 has been formed by pressing the wall of thesocket 6 to provide a rib 32 complementary to the groove 30, rib 32 tobe received in an inner circumferential groove 34 in an insulatingsleeve forming part 38, for eqample, of a distributor head, to preventrelative axial movement between the member 6 and the sleeve 33. Thesleeve 38 has a bell mouth 40 to act as a guide for inserting theferrule 2 into the bore 4. To remove the ferrule 2 from the bore 4, thecable 8 is pulled in the direction indicated by the arrow in FIGURE 4.The detent rib 28 is cammed by the right hand portion of the wall of thegroove 30 and is depressed so that it can pass along the bore 4 in thedirection of the arrow.

When the rib 28 has been fully depressed, the detent rib 26 reaches awall portion adjacent the aforesaid wall portion and is in turndepressed to pass along the bore 4 in the same manner as detent rib 28.The forces required to depress the two ribs thus reach their maximumvalue at different periods during withdrawal of the ferrule 2. The wedgeshaped construction of the detent ribs 26 and 28 facilitates theinsertion of the ferrule 2 into the bore 4.

Since the ferrule 2 surrounds the end of cable 8 throughout the lengthof the ferrule, the ferrule is not readily deformed if the cable ispulled in the transverse direction of the ferrule. Since the tongues 22,24 and the detent ribs 26 and 28 and the spears 10 and 36 are allintegral with the ferrule 2, a ferrule blank can readily be stamped froma sheet of metal, e.g., brass, and subsequently rolled to form theferrule in a rapid and inexpensive manner.

Since the right hand end, see FIGURE 4, of the detent rib 28 abuts onewall of the groove 30, and the left hand end of the detent rib 26 abutsthe opposite wall of the groove 30 relative axial movement between theferrule 2 and socket 6 is prevented. As can be noted the plug can easilybe removed from the socket and is of simple design, yet rugged andfoolproof in actual operation.

While there have been illustrated and described fundamental novelfeatures of the invention, it will be understood that various omissionsand substitutions and changes in the form and details of the deviceillustrated and its operation may be made by those skilled in the artwithout departing from the spirit of the invention. It is the intention,therefore, to be limited only as indicated by the scope of the followingclaims.

We claim:

1. For use to connect electrically with a socket having an internalannular reress, a metallic plug having a plurality of detent projectionsor resilient cooperation with said recess to retain the plug in thesocket, said projections being offset from one another along theinsertion axis of the plug for sequential depression thereof uponinsertion and Withdrawal of the plug into and from the socket, themaximum axial spacing of the projections being less than the width ofthe recess in which it is intended to engage, each projection defining atapered surface inclined towards the longitudinal axis of the plug inthe insertion direction thereof which merges into another taperedsurface extending in an opposite direction with respect to saidfirst-mentioned tapered surface, the inclined surface of the projectionnearest the insertion end of the plug adapted to wedgingly engage aninterior Wall portion of the socket adjacent said recess, the othertapered surface of the other projection adapted to engage said recess.

2. An electrical connector comprising a socket having an internalannular recess, a plug receivable in said socket and including a ferrulefor crimping about an electrical lead wire and a pair of opposed tonguesdisposed for independent resilient depression, a detent rib on each ofsaid tongues defining a pair of detent ribs cooperable with said recessto retain the plug in the socket, one rib being offset from anotheralong the insertion axis of the plug for sequential depression thereofupon withdrawal of the plug from the socket, the axial spacing of saidribs being less than the width of said recess, the detent rib nearestthe insertion end of the plug having a tapered surface inclined towardsthe longitudinal axis of the plug in the insertion direction thereof forWedging engagement with the interior surface of the socket, and theother detent rib having a surface facing oppositely to the insertiondirection for resilient engagement With the recess to drive the inclinedsurface into tight Wedging engagement with the interior surface of thesocket.

References Cited by the Examiner UNITED STATES PATENTS 1,233,031 7/1917Cook 339183 1,835,000 12/1931 Berthold 339256 1,926,163 9/1933 Mohr 339X 2,246,901 6/1941 Schwarzmann 339100 X 2,463,826 3/ 1949 Thacker.2,651,025 9/1953 Elliott 339-97 2,917,612 12/1959 Chabot 3392582,948,877 8/1960 Batcheller 339256 X 3,002,170 9/1961 Clouthier 339217 X3,077,523 2/1963 Clewes 339256 X FOREIGN PATENTS 1,193,096 4/1959France.

347,081 1/ 1922 Germany.

327,553 4/1930 Great Britain.

437,546 10/1935 Great Britain.

JOSEPH D. SEERS, Primary Examiner.

1. FOR USE TO CONNECT ELECTRICALLY WITH A SOCKET HAVING AN INTERNALANNULAR RECESS, A METALLIC PLUG HAVING A PLURALITY OF DETENT PROJECTIONSOR RESILIENT COOPERATION WITH SAID RECESS TO RETAIN THE PLUG IN THESOCKET, SAID PROJECTIONS BEING OFFSET FROM ONE ANOTHER ALONG THEINSERTION AXIS OF THE PLUG FOR SEQUENTIAL DEPRESSION THEREOF UPONINSERTION AND WITHDRAWAL OF THE PLUG INTO AND FROM THE SOCKET, THEMAXIMUM AXIAL SPACING OF THE PROJECTIONS BEING LESS THAN THE WIDTH OFTHE RECESS IN WHICH IT IS INTENDED TO ENGAGE, EACH PROJECTION DEFINING ATAPERED SURFACE INCLINED TOWARDS THE LONGITUDINAL AXIS OF THE PLUG INTHE INSERTION DIRECTION THEREOF WHICH MERGES INTO ANOTHER TAPEREDSURFACE EXTENDING IN AN OPPOSITE DIRECTION WITH RESPECT TO SAIDFIRST-MENTIONED TAPERED SURFACE, THE INCLINED SURFACE OF THE PROJECTIONNEAREST THE INSERTION END OF THE PLUG ADAPTED TO WEDGINGLY ENGAGE ANINTERIOR WALL PORTION OF THE SOCKET ADJACENT SAID RECESS, THE OTHERTAPERED SURFACE OF THE OTHER PROJECTION ADAPTED TO ENGAGE SAID RECESS.